tests/test_qsbr_gc.c

   1 /*
   2  * test_urcu_gc.c
   3  *
   4  * Userspace RCU library - test program (with baatch reclamation)
   5  *
   6  * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #define _GNU_SOURCE
  24 #include "../config.h"
  25 #include <stdio.h>
  26 #include <pthread.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30 #include <sys/wait.h>
  31 #include <unistd.h>
  32 #include <stdio.h>
  33 #include <assert.h>
  34 #include <sys/syscall.h>
  35 #include <sched.h>
  36 #include <errno.h>
  37
  38 #include <urcu/arch.h>
  39
  40 /* hardcoded number of CPUs */
  41 #define NR_CPUS 16384
  42
  43 #if defined(_syscall0)
  44 _syscall0(pid_t, gettid)
  45 #elif defined(__NR_gettid)
  46 static inline pid_t gettid(void)
  47 {
  48         return syscall(__NR_gettid);
  49 }
  50 #else
  51 #warning "use pid as tid"
  52 static inline pid_t gettid(void)
  53 {
  54         return getpid();
  55 }
  56 #endif
  57
  58 #define _LGPL_SOURCE
  59 #include <urcu-qsbr.h>
  60
  61 struct test_array {
  62         int a;
  63 };
  64
  65 static volatile int test_go, test_stop;
  66
  67 static unsigned long wdelay;
  68
  69 static struct test_array *test_rcu_pointer;
  70
  71 static unsigned long duration;
  72
  73 /* read-side C.S. duration, in loops */
  74 static unsigned long rduration;
  75 static unsigned int reclaim_batch = 1;
  76
  77 struct reclaim_queue {
  78         void **queue;   /* Beginning of queue */
  79         void **head;    /* Insert position */
  80 };
  81
  82 static struct reclaim_queue *pending_reclaims;
  83
  84
  85 static inline void loop_sleep(unsigned long l)
  86 {
  87         while(l-- != 0)
  88                 cpu_relax();
  89 }
  90
  91 static int verbose_mode;
  92
  93 #define printf_verbose(fmt, args...)            \
  94         do {                                    \
  95                 if (verbose_mode)               \
  96                         printf(fmt, args);      \
  97         } while (0)
  98
  99 static unsigned int cpu_affinities[NR_CPUS];
 100 static unsigned int next_aff = 0;
 101 static int use_affinity = 0;
 102
 103 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 104
 105 #ifndef HAVE_CPU_SET_T
 106 typedef unsigned long cpu_set_t;
 107 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
 108 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
 109 #endif
 110
 111 static void set_affinity(void)
 112 {
 113         cpu_set_t mask;
 114         int cpu;
 115         int ret;
 116
 117         if (!use_affinity)
 118                 return;
 119
 120 #if HAVE_SCHED_SETAFFINITY
 121         ret = pthread_mutex_lock(&affinity_mutex);
 122         if (ret) {
 123                 perror("Error in pthread mutex lock");
 124                 exit(-1);
 125         }
 126         cpu = cpu_affinities[next_aff++];
 127         ret = pthread_mutex_unlock(&affinity_mutex);
 128         if (ret) {
 129                 perror("Error in pthread mutex unlock");
 130                 exit(-1);
 131         }
 132
 133         CPU_ZERO(&mask);
 134         CPU_SET(cpu, &mask);
 135 #if SCHED_SETAFFINITY_ARGS == 2
 136         sched_setaffinity(0, &mask);
 137 #else
 138         sched_setaffinity(0, sizeof(mask), &mask);
 139 #endif
 140 #endif /* HAVE_SCHED_SETAFFINITY */
 141 }
 142
 143 /*
 144  * returns 0 if test should end.
 145  */
 146 static int test_duration_write(void)
 147 {
 148         return !test_stop;
 149 }
 150
 151 static int test_duration_read(void)
 152 {
 153         return !test_stop;
 154 }
 155
 156 static unsigned long long __thread nr_writes;
 157 static unsigned long long __thread nr_reads;
 158
 159 static unsigned int nr_readers;
 160 static unsigned int nr_writers;
 161
 162 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 163 static
 164 unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_writes;
 165
 166
 167 void rcu_copy_mutex_lock(void)
 168 {
 169         int ret;
 170         ret = pthread_mutex_lock(&rcu_copy_mutex);
 171         if (ret) {
 172                 perror("Error in pthread mutex lock");
 173                 exit(-1);
 174         }
 175 }
 176
 177 void rcu_copy_mutex_unlock(void)
 178 {
 179         int ret;
 180
 181         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 182         if (ret) {
 183                 perror("Error in pthread mutex unlock");
 184                 exit(-1);
 185         }
 186 }
 187
 188 void *thr_reader(void *_count)
 189 {
 190         unsigned long long *count = _count;
 191         struct test_array *local_ptr;
 192
 193         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 194                         "reader", pthread_self(), (unsigned long)gettid());
 195
 196         set_affinity();
 197
 198         rcu_register_thread();
 199
 200         while (!test_go)
 201         {
 202         }
 203         smp_mb();
 204
 205         for (;;) {
 206                 _rcu_read_lock();
 207                 local_ptr = _rcu_dereference(test_rcu_pointer);
 208                 debug_yield_read();
 209                 if (local_ptr)
 210                         assert(local_ptr->a == 8);
 211                 if (unlikely(rduration))
 212                         loop_sleep(rduration);
 213                 _rcu_read_unlock();
 214                 nr_reads++;
 215                 /* QS each 1024 reads */
 216                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 217                         _rcu_quiescent_state();
 218                 if (unlikely(!test_duration_read()))
 219                         break;
 220         }
 221
 222         rcu_unregister_thread();
 223
 224         *count = nr_reads;
 225         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 226                         "reader", pthread_self(), (unsigned long)gettid());
 227         return ((void*)1);
 228
 229 }
 230
 231 static void rcu_gc_clear_queue(unsigned long wtidx)
 232 {
 233         void **p;
 234
 235         /* Wait for Q.S and empty queue */
 236         synchronize_rcu();
 237
 238         for (p = pending_reclaims[wtidx].queue;
 239                         p < pending_reclaims[wtidx].head; p++) {
 240                 /* poison */
 241                 if (*p)
 242                         ((struct test_array *)*p)->a = 0;
 243                 free(*p);
 244         }
 245         pending_reclaims[wtidx].head = pending_reclaims[wtidx].queue;
 246 }
 247
 248 /* Using per-thread queue */
 249 static void rcu_gc_reclaim(unsigned long wtidx, void *old)
 250 {
 251         /* Queue pointer */
 252         *pending_reclaims[wtidx].head = old;
 253         pending_reclaims[wtidx].head++;
 254
 255         if (likely(pending_reclaims[wtidx].head - pending_reclaims[wtidx].queue
 256                         < reclaim_batch))
 257                 return;
 258
 259         rcu_gc_clear_queue(wtidx);
 260 }
 261
 262 void *thr_writer(void *data)
 263 {
 264         unsigned long wtidx = (unsigned long)data;
 265 #ifdef TEST_LOCAL_GC
 266         struct test_array *old = NULL;
 267 #else
 268         struct test_array *new, *old;
 269 #endif
 270
 271         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 272                         "writer", pthread_self(), (unsigned long)gettid());
 273
 274         set_affinity();
 275
 276         while (!test_go)
 277         {
 278         }
 279         smp_mb();
 280
 281         for (;;) {
 282 #ifndef TEST_LOCAL_GC
 283                 new = malloc(sizeof(*new));
 284                 new->a = 8;
 285                 old = _rcu_xchg_pointer(&test_rcu_pointer, new);
 286 #endif
 287                 rcu_gc_reclaim(wtidx, old);
 288                 nr_writes++;
 289                 if (unlikely(!test_duration_write()))
 290                         break;
 291                 if (unlikely(wdelay))
 292                         loop_sleep(wdelay);
 293         }
 294
 295         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 296                         "writer", pthread_self(), (unsigned long)gettid());
 297         tot_nr_writes[wtidx] = nr_writes;
 298         return ((void*)2);
 299 }
 300
 301 void show_usage(int argc, char **argv)
 302 {
 303         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 304 #ifdef DEBUG_YIELD
 305         printf(" [-r] [-w] (yield reader and/or writer)");
 306 #endif
 307         printf(" [-d delay] (writer period (us))");
 308         printf(" [-c duration] (reader C.S. duration (in loops))");
 309         printf(" [-v] (verbose output)");
 310         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 311         printf("\n");
 312 }
 313
 314 int main(int argc, char **argv)
 315 {
 316         int err;
 317         pthread_t *tid_reader, *tid_writer;
 318         void *tret;
 319         unsigned long long *count_reader;
 320         unsigned long long tot_reads = 0, tot_writes = 0;
 321         int i, a;
 322
 323         if (argc < 4) {
 324                 show_usage(argc, argv);
 325                 return -1;
 326         }
 327
 328         err = sscanf(argv[1], "%u", &nr_readers);
 329         if (err != 1) {
 330                 show_usage(argc, argv);
 331                 return -1;
 332         }
 333
 334         err = sscanf(argv[2], "%u", &nr_writers);
 335         if (err != 1) {
 336                 show_usage(argc, argv);
 337                 return -1;
 338         }
 339
 340         err = sscanf(argv[3], "%lu", &duration);
 341         if (err != 1) {
 342                 show_usage(argc, argv);
 343                 return -1;
 344         }
 345
 346         for (i = 4; i < argc; i++) {
 347                 if (argv[i][0] != '-')
 348                         continue;
 349                 switch (argv[i][1]) {
 350 #ifdef DEBUG_YIELD
 351                 case 'r':
 352                         yield_active |= YIELD_READ;
 353                         break;
 354                 case 'w':
 355                         yield_active |= YIELD_WRITE;
 356                         break;
 357 #endif
 358                 case 'a':
 359                         if (argc < i + 2) {
 360                                 show_usage(argc, argv);
 361                                 return -1;
 362                         }
 363                         a = atoi(argv[++i]);
 364                         cpu_affinities[next_aff++] = a;
 365                         use_affinity = 1;
 366                         printf_verbose("Adding CPU %d affinity\n", a);
 367                         break;
 368                 case 'b':
 369                         if (argc < i + 2) {
 370                                 show_usage(argc, argv);
 371                                 return -1;
 372                         }
 373                         reclaim_batch = atol(argv[++i]);
 374                         break;
 375                 case 'c':
 376                         if (argc < i + 2) {
 377                                 show_usage(argc, argv);
 378                                 return -1;
 379                         }
 380                         rduration = atol(argv[++i]);
 381                         break;
 382                 case 'd':
 383                         if (argc < i + 2) {
 384                                 show_usage(argc, argv);
 385                                 return -1;
 386                         }
 387                         wdelay = atol(argv[++i]);
 388                         break;
 389                 case 'v':
 390                         verbose_mode = 1;
 391                         break;
 392                 }
 393         }
 394
 395         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 396                 duration, nr_readers, nr_writers);
 397         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 398         printf_verbose("Reader duration : %lu loops.\n", rduration);
 399         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 400                         "main", pthread_self(), (unsigned long)gettid());
 401
 402         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 403         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 404         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 405         tot_nr_writes = malloc(sizeof(*tot_nr_writes) * nr_writers);
 406         pending_reclaims = malloc(sizeof(*pending_reclaims) * nr_writers);
 407         if (reclaim_batch * sizeof(*pending_reclaims[i].queue)
 408                         < CACHE_LINE_SIZE)
 409                 for (i = 0; i < nr_writers; i++)
 410                         pending_reclaims[i].queue = calloc(1, CACHE_LINE_SIZE);
 411         else
 412                 for (i = 0; i < nr_writers; i++)
 413                         pending_reclaims[i].queue = calloc(reclaim_batch,
 414                                         sizeof(*pending_reclaims[i].queue));
 415         for (i = 0; i < nr_writers; i++)
 416                 pending_reclaims[i].head = pending_reclaims[i].queue;
 417
 418         next_aff = 0;
 419
 420         for (i = 0; i < nr_readers; i++) {
 421                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 422                                      &count_reader[i]);
 423                 if (err != 0)
 424                         exit(1);
 425         }
 426         for (i = 0; i < nr_writers; i++) {
 427                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 428                                      (void *)(long)i);
 429                 if (err != 0)
 430                         exit(1);
 431         }
 432
 433         smp_mb();
 434
 435         test_go = 1;
 436
 437         sleep(duration);
 438
 439         test_stop = 1;
 440
 441         for (i = 0; i < nr_readers; i++) {
 442                 err = pthread_join(tid_reader[i], &tret);
 443                 if (err != 0)
 444                         exit(1);
 445                 tot_reads += count_reader[i];
 446         }
 447         for (i = 0; i < nr_writers; i++) {
 448                 err = pthread_join(tid_writer[i], &tret);
 449                 if (err != 0)
 450                         exit(1);
 451                 tot_writes += tot_nr_writes[i];
 452                 rcu_gc_clear_queue(i);
 453         }
 454
 455         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 456                tot_writes);
 457         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 458                 "nr_writers %3u "
 459                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu "
 460                 "batch %u\n",
 461                 argv[0], duration, nr_readers, rduration,
 462                 nr_writers, wdelay, tot_reads, tot_writes,
 463                 tot_reads + tot_writes, reclaim_batch);
 464         free(tid_reader);
 465         free(tid_writer);
 466         free(count_reader);
 467         free(tot_nr_writes);
 468         for (i = 0; i < nr_writers; i++)
 469                 free(pending_reclaims[i].queue);
 470         free(pending_reclaims);
 471
 472         return 0;
 473 }